Answer:
Yes, if the doctrine of comparative fault followed then it will reduce the compensation for the actual damage. The reason is that both parties were negligent in exercising the level of care and hence the plaintiff who suffered injury must be compensated for lower damage not for actual damage.
Step-by-step explanation:
The reason is that if the plaintiff was wearing the seat belt then he would had suffered lower damages than the actual one so the doctrine of comparative fault says that he must be compensated for the lower damage as the negligence of the defendant resulted in injury from car accident but it was also due to the negligence of plaintiff as well.